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Biomedical subjects

E Ferri

Publications and source records attributed to E Ferri.

At least 55 records · Page 3Linked to original sources
PubMed1994

Interaction between reactive oxygen species and coenzyme Q10 in an aprotic medium: a cyclic voltammetry study.

The involvement of coenzyme Q (CoQ) as an antioxidant agent in several oxidative processes both in vitro and in vivo is nowadays pointed out by several biochemical and clinical studies, but the chemical mechanisms of this action are not yet unequivocally established. Electrochemistry provides very useful techniques for the analysis of the kinetics and thermodynamics, and mechanisms of chemical phenomena involving electron transfers, e.g. in the case of radical reactions. In the present study we used cyclic voltammetry to investigate the interactions between oxygen radicals and ubiquinone in aprotic medium, a condition similar to that existing in the biological membranes. The results obtained showed that ubiquinone is more easily reduced than oxygen, ruling out the possibility of an electron transfer from semiquinone to oxygen to produce superoxide radicals. On the contrary, it was demonstrated that fully reduced quinone is able to scavenge the superoxide radical, by reduction to peroxide ion, lowering actually the oxidative potential in the medium.

Antioxidants↗
PubMed1994

The Italian Artificial Heart Program.

In Italy, artificial heart development was promoted by virtue of a special program on technological and industrial development in areas related to cardiology and cardiosurgery. A first prototype series of electromechanical total artificial hearts (TAHs) and ventricular assist devices (VADs), with ball-screw-based actuation technology, has been developed, and preliminary bench tests and short-term animal implant experiments were performed. The project started with analysis and development of existing TAH and VAD models, and it included a fill-sensor-free control scheme and anatomical fitting studies using a three-dimensional computer model of the chest cavity. Second-generation prototypes are currently being developed, and they are scheduled for medium-term bench and in vivo testing by early 1994.

Animals↗
PubMed1992

Prolactin responses to domperidone in chronic schizophrenia.

The prolactin response to 20 mg of domperidone, a peripheral dopamine receptor antagonist, was evaluated in a group of 17 male, drug-free, elderly, chronic schizophrenic patients and 8 age-matched male normal control subjects. Both groups of subjects were receiving a variety of nonpsychotropic medications not known to affect the prolactin response to dopamine receptor antagonists. Basal plasma prolactin levels did not differ between the two groups. However, the prolactin response following domperidone was significantly greater in the schizophrenic patients, although plasma domperidone levels did not differ between the two groups. This effect is opposite to the previously reported effect of domperidone in young schizophrenic patients compared with age-matched control subjects (Nerozzi et al., 1990). The prolactin response to domperidone was markedly smaller in the old compared with the young normal control subjects, whereas the young and old schizophrenic patients had identical responses. Possible explanations for these results are considered, especially the possibility of abnormalities in the release of dopamine and pituitary D2 dopamine receptors in the elderly schizophrenic patients compared with age-matched normal control subjects.

Aged↗
PubMed1992

Kinetic uptake of etanidazole in lung carcinoma and normal tissue in vivo.

Thirty-four patients affected by primary pulmonary carcinoma or in a state of recurrence after surgery were analyzed and 2g/m2 of etanidazole was administered intravenously. After 30 min (group A), 60 min (group B), and 120 min (group C), both the bronchus affected by the carcinoma and the contralateral bronchus were biopsied. Of the 34 patients, 24 had histologically proven carcinoma and were enrolled in the study. Etanidazole determination was carried out with a polarographic method both in plasma and tissue. The results obtained indicate that the most favorable concentration of etanidazole in the tissue is at 30 min after administration and at this point is most beneficial when associated with radiotherapy. The tumor/plasma ratio of etanidazole examined in three phases is relatively higher than that noted with HPLC; however, it is compatible with the methodology used and previous studies carried out on other tumors.

Aged↗
PubMed1992

Effects of the association of alpha and beta-blocking agents in glaucoma.

Twenty patients with POAG and early visual field changes, already under treatment with 0.5% timolol were randomly assigned to additional topical treatment with 0.5% dapiprazole or placebo. After six months of treatment no differences were observed between the groups for what concerns visual field. After six months of treatment visual field, visual flicker discrimination and contrast sensitivity proved to be constant without differences between the groups. On the contrary, mean IOP was found to be significantly lower in the dapiprazole group.

Adrenergic alpha-Antagonists↗
PubMed1991

Chemiluminescent assay for the detection of viral and plasmid DNA using digoxigenin-labeled probes.

A dot-blot hybridization immunoenzymatic assay with a chemiluminescent endpoint was developed for the rapid and sensitive detection of viral and plasmid DNAs. Digoxigenin-labeled probes were used to detect cytomegalovirus, parvovirus B19, and plasmid pBR328 DNAs. Hybridized probes were immunoenzymatically visualized by anti-digoxigenin Fab fragments labeled with alkaline phosphatase, and adamantyl 1,2-dioxetane phenyl phosphate was used as chemiluminescent substrate. Results were recorded by instant photographic films. The chemiluminescent hybridization assay was performed in about 8 hr and was able to detect as little as 50-10 fg of homologous target DNA.

Cytomegalovirus↗
PubMed1991

Methodological problems of direct bioluminescent ADP assay in platelets and erythrocytes.

We have developed a method for ADP bioluminescent measurement in platelets and erythrocytes which complements our previous method for ATP assay. When the different parameters of the system under investigation are taken into account, a linea range between 10(-9) and 10(-7) g/ml can be obtained without incubation or troublesome extraction. This makes the method easy and useful for identifying any disease-induced alterations in ATP and/or ADP levels in these blood cells. The data obtained correlate well with those of a bioluminescent method requiring extraction with ethanol/EDTA and incubation, giving the reference intervals of 3.5-5.5 mumol/10(11) PLT for ATP determination and 1.9-3.7 mumol/10(11) PLT for ADP determination in platelets, and 3.2-3.8 mumol/g Hgb for ATP determination and 0.56-0.73 mumol/g Hgb for ADP in erythrocytes. This assay was applied to quality control on blood bags in transfusion centers and proved to be a rapid and reliable method for testing the viability of stored blood cells.

Adenosine Diphosphate↗
PubMed1991

Chemiluminescence dot blot hybridization assay for detection of B19 parvovirus DNA in human sera.

A chemiluminescence dot blot hybridization assay was used for the detection of B19 parvovirus DNA in human sera by using digoxigenin-labeled probes. The probes were revealed immunoenzymatically by use of anti-digoxigenin Fab fragments conjugated with alkaline phosphatase. The chemiluminescence signal was obtained by reacting the labeled probe-target complex with an enzyme-triggerable dioxetane substrate. The emitted photons were detected with instant photographic films. In the search for B19 parvovirus DNA, 2,808 serum samples were analyzed.

DNA Probes↗
PubMed1990

Bioluminescent flow sensor for the determination of L-(+)-lactate.

The amount of L-lactate in biological fluids (serum, plasma and cerebrospinal fluid) was determined by monitoring the reduced form of nicotinamide adenine dinucleotide (NADH) produced by immobilised lactate dehydrogenase (LDH), with bacterial bioluminescent enzymes immobilised on a separate nylon coil. The LDH catalysed the reaction of L-lactate with NAD; this reaction took place in a nylon coil that preceded the coil for the bioluminescent detection. The co-immobilisation of alanine aminotransferase (ALT) with LDH improved the lactate transformation by 117-183%. The response was linear from 0.1 to 50 micron mol l(-1) at 25 degrees C for the LDH - ALT reactor. The intra- and inter-assay coefficients of variation were less than 5% and the recoveries ranged from 93 to 106%. The results agreed well with those obtained with a spectrophotometric method and with the normal reference values.

Alanine Transaminase↗
PubMed1989

Methodological problems of direct bioluminescent ATP assay in platelets and erythrocytes.

Direct bioluminescent ATP determination in platelets and erythrocytes involves the study of different parameters which are discussed here. Some parameters are linked to the bioluminescent reaction and to the analyte (ATP); others have regard to the biological matrix. The composition of bioluminescent reagents and the preparation and conservation of the ATP standard, also in the presence of excipients, are among the first given. Matrix problems involve cell characteristics related to age and form, lysis resistance and the possible formation of aggregates (platelets) that may inhibit the complete release of ATP. For these reasons we used the most efficient ATP release agent with the lowest inhibitory effect on luciferase. The data obtained correlate well with a bioluminescent method requiring extraction with ethanol/EDTA, and therefore more time, for ATP determination in platelets and erythrocytes.

Adenosine Diphosphate↗
PubMed1988

[Presentation of a case of spinal osteoid osteoma causing dorsal scoliosis. Role of high resolution CT].

A case of vertebral osteoid osteoma in a 19 years old female is described. The tumor was located at D7 right peduncle and was responsible for a mild left convex curve dorso-lumbar scoliosis. The patient had been complaining for 3 years because of a stablike pain at medio-dorsal level. The symptomatology was exacerbated by erect position, during the night and was relieved by salicylic acid. Diagnosis was suspected on the basis of scintigraphic and computed tomographic features and confirmed at surgery. Limited value of plain films and the importance of bony scintigraphy and high resolution computed tomography to establish the localization and nature of the lesion are stressed.

Adult↗
PubMedDate not supplied

Continuous-flow bioluminescent determination of ATP in platelets using firefly luciferase immobilized on epoxy methacrylate.

Firefly luciferase was immobilized on epoxy methacrylate beads and used for a continuous-flow assay of ATP extracted from platelets. The immobilized luciferase had a half-life of 3 days at 25 degrees C; there was a 25% recovery of luciferase activity upon immobilization, and ca 50 reactors were made from 1 mg of commercial enzyme. The sensitivity of the assay was 0.3 pmol of ATP, and the response was linear between 1 and 500 pmol of ATP. The ATP content of platelets obtained with the present method correlated well with those obtained using soluble luciferase.

Adenosine Triphosphate↗